Weather officials on Thursday urged people to take extra care along the coast as waves from a major winter storm in the Southern Hemisphere lashed the local shoreline.

This being San Diego, the warnings lured hard-core surfers out for a chance to ride what many called one of the biggest south swells in years. Old-timers, kids and sunbathers watched from the cliff tops, taking pictures and offering a running commentary on the waves and wipeouts below.

The much-hyped system didn’t disappoint and it’s expected to continue pushing huge waves ashore through the Labor Day weekend.

“This one has got some anger to it,” Jason Matuza of San Diego said while peeling off his wet suit at Windansea. “I just happened to be off (work), but I am sure a lot of people are calling in sick.”

Eight-foot waves were common along the coastline, a rarity during the summer. Matuza said he scouted several spots before landing at the famous La Jolla break.

“This was the biggest, best spot we saw,” he said.

He was sobered by watching three rescues and two broken boards when he arrived. After he emerged from the water, he said he had to work hard for his rides and the waves didn’t have ideal shape. “We were all taking a beating,” he said. “It’s a little gnarly on the inside.”

State lifeguard supervisor Pat Caldwell said the largest south-facing wave sets Thursday were 10 to 15 feet. At times, surfers on their boards at the bottom of the swells had waves that were twice their height overhead, he said. Few swimmers were in the water.

“It was pretty dangerous for the inexperienced swimmer, and even for experienced swimmers," Caldwell said. "It’s been quite challenging and treacherous.”

Caldwell said the danger lies not only in the size of the waves, but also the fact that the large sets can be 15 to 20 minutes apart. That can lull some swimmers to go into the water when it appears that there are no waves, and they get caught when the big ones arrive.

At Tamarack beach in Carlsbad, Caldwell said an inexperienced surfer needed to be rescued because he got caught outside the big waves and knew he could not make it to shore. “He was waving for help and afraid to catch a wave or to paddle in,” Caldwell said, adding that rip-current conditions in places extended a quarter-mile out to sea.

San Diego lifeguards made 15 to 20 rescues, some of them surfers, lifeguard Lt. Nick Lerma said. The surf was “huge” at Windansea, where one lifeguard who is also a professional surfer said that some waves may have topped 15 feet, Lerma said.

The Ocean Beach Pier was closed Thursday because the high surf damaged a wooden railing.

At Windansea, Jaelynn Denaro of La Jolla munched Ritz crackers filled with peanut butter and watched from the sandstone shoreline as her adult son ripped across the waves. “He was surfing yesterday and said I should have been out there with the camera,” Denaro said, Nikon in hand.

So does she cringe as she watches, worrying about the worst?

“It doesn’t scare me,” she said. “When it gets to 30-foot waves, I would be scared.”

No threat of that, according to the National Weather Service. The agency’s high surf advisory is expected to continue through Friday afternoon, producing waves from five to nine feet and sets to 12 feet on exposed southwest-facing beaches.

The weather service said to expect higher-than-average waves and strong rip currents through the Labor Day weekend as the system peters out.

“We receive about 50 swells a year from storms in the Southern Hemisphere,” said Sean Collins, chief forecaster at surfline.com. “Most of those swells create surf of three feet on the wave face, 40 percent of those swells are over five feet, 10 percent are over eight feet. This swell is obviously in the top 10 percent ... and will probably be the largest southern hemisphere swell we’ve received in the past few years.”

While the local conditions didn’t outdo big wave action in places like Hawaii and Tahiti, it was big enough draw interest from surf legends. “I just spoke with Kelly Slater this afternoon about where to surf today and I know there are quite a few other pro surfers looking for the best spots,” Collins said Wednesday night.

Garth Engelhorn of Encinitas showed up on the shoreline at about 6 a.m. Thursday looking for his best spot. He eventually landed at La Jolla break called Horseshoe and spent a few hours in the water. Engelhorn said storms from New Zealand often fizzle out and disappoint. This one was different, producing enough good waves to make him late for work.

“It looks like the swell is going to stay around so I am definitely going to concoct some sort of a plan to surf early Friday,” he said.

He’s not the only one. With the holiday weekend coming up, “I expect all of the lifeguards along the San Diego coast to be extremely busy,” Caldwell said.